(1) Field of Invention
This invention refers to a method and a device for diagnosing technical devices, especially pumps and valves, that are disposed within an industrial installation used in the processing industry, with disturbance variables that affect the devices and influence the service life thereof being detected by means of sensory technology with the data of said disturbance variables being processed in a simulative manner in order to determine the expected service life of each device.
(2) Description of Related Art
The area of application of this invention extends to industrial installations, such as technical process installations, mechanical production installations and similar. Within these installations, individual technical devices are linked to form a system to produce a product, mainly by fully automatic means. For the automatic production of products within those industrial installations that are of interest here, the individual technical devices are usually also automatically monitored with respect to their wear state. The wear state of a device within the industrial installation is diagnosed to enable devices that require maintenance or repair to be identified in order for an appropriate, time-saving maintenance or repair of the industrial installation be carried out without a high manual diagnostic expense.
In the general prior art, generic technical devices are known which include electronic diagnosis means that form a sort of maintenance activator. Technical devices of this kind can use sensory technology to detect events that trigger maintenance or repair and output a message immediately a maintenance case occurs. Such a maintenance case can, for example, be triggered by a defective pipe within the technical device, the defect of which has been determined by sensory technology. A disadvantage of this type of diagnosis is that the message regarding a required maintenance case does not take place until a fault or functional limitation of the technical device has already occurred. Because of this reactive diagnosis, the occurrence of a maintenance case is often unpredicted and sudden, which in extreme cases leads to a correspondingly sudden failure of the complete industrial installation. This in turn can lead to unforeseen production failures.
U.S. Pat. No. 5,533,413 discloses a method and a device for diagnosis of technical devices disposed within an industrial installation that avoids the aforementioned disadvantages in that a type of service life clock is assigned by simulatory means to each technical device. The disturbance variables such as temperature rise, pressure increases and vibration stresses that affect the technical devices and influence the service life thereof are detected by sensory means. The data obtained in this way are then processed by technical simulatory means to determine the expected service life of the device. For simulation, a simulation model of the associated technical device on which the disturbance variables influencing the service life act as input data is created and parameterized. The main result of the simulation is that it enables the expected service life of the technical device to be calculated. This reduces if the disturbance variables influencing the service life occur frequently over a long duration and at high intensity, whereas in the reverse case the expected service life increases if the disturbance variables influencing the service life occur seldom, over a short time interval and with less intensity.
Although this technical solution provides a very reliable prognosis with regard to the expected service life of the individual technical device, the type of damage to be expected that the disturbance triggers, for example a defect in a pipe in the technical device due to leakage or blockage, is completely unspecified. Therefore, the operator of the industrial installation receives only information regarding when and on what technical device a disturbance is to be expected. Information on the type of disturbance to be expected and the correct maintenance measures for rectifying this disturbance are, however, absent. Therefore, despite timely prognosis of a fault in a technical device of an industrial installation, long shutdown times can still occur because the required maintenance and repair measures may be unpredictably expensive or it may not be possible to obtain the correct replacement parts in good time.